dd-01_brochure[1].pdf

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FOR SAFE FIRING

OF BLACK LIQUOR

IN RECOVERY BOILERS

SB:DD-01/1

K-PATENTS DIGITAL DIVERT CONTROL SYSTEM DD-01


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APPLICATION


SAFE OPERASAFE OPERASAFE OPERASAFE OPERASAFE OPERATION OFTION OFTION OFTION OFTION OF

RECORECORECORECORECOVERY BOILERSVERY BOILERSVERY BOILERSVERY BOILERSVERY BOILERS REQUIRESREQUIRESREQUIRESREQUIRESREQUIRES

KKKKK-P-P-P-P-PAAAAATENTS DIGITTENTS DIGITTENTS DIGITTENTS DIGITTENTS DIGITAL DIVERAL DIVERAL DIVERAL DIVERAL DIVERTTTTT

SYSTEMSYSTEMSYSTEMSYSTEMSYSTEMFeeding low concentrations of black liquorsolids to a kraft chemical recovery boiler burnercan cause a steam explosion. A digital divertcontrol system is required to ensure safeoperation.

BLRBAC REGULABLRBAC REGULABLRBAC REGULABLRBAC REGULABLRBAC REGULATIONSTIONSTIONSTIONSTIONSThe Black Liquor Recovery Boiler AdvisoryCommittee (BLRBAC) recommends standardsfor safe firing of black liquor and suggestsusing an automatic black liquor divert controlsystem to ensure that weak liquor is not fedinto the boiler.

BLRBAC requires that if the black liquorconcentration falls below 58%, the system shallgive an audible alarm signal, and go to adiversion function to direct the black liquor flowto by-pass the boiler. A concentration value of60% shall give an audible alarm to notify theusers about the low concentration.Furthermore, the control unit shall check thatthe difference between the two individualrefractometer signals does not exceed 2%.

These close tolerances require digital circuitrywhich eliminates drift.


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Indicatingtransmitter B

Sensor A

Sensor B

Indicatingtransmitter A

Divertcontrol unit

Divert signal

Audible signal

SYSTEM DECISION LOGICS

2. ST2. ST2. ST2. ST2. STAAAAATUS OF THE REFRACTTUS OF THE REFRACTTUS OF THE REFRACTTUS OF THE REFRACTTUS OF THE REFRACTOMETERSOMETERSOMETERSOMETERSOMETERS

OPTICAL IMAGE

DETECTION

The K-Patents Digital Divert Control System isbuilt in strict accordance with therecommendations of BLRBAC. The system

includes two process refractometers withretraction valves installed in the main blackliquor line, two indicating transmitters and adivert control panel.

As an added benefit, each refractometer is acompletely independent measurement system.Each system sends a separate output signal,which can be use by the control system or DCS.

The divert decision is controlled from the divertcontrol unit. The built-in diagnostics providesthree levels of decision logics for a tight control.

1. ALARMS1. ALARMS1. ALARMS1. ALARMS1. ALARMS

The K-Patents Process Refractometer uses anoptical image detection algorithm, which

locates the shadow line with higher precisionand reliablity than the fixed threshold method.The quality of the optical image ismathematically checked and constantlymonitored. An incorrect image form gives analarm.

3. DIVER3. DIVER3. DIVER3. DIVER3. DIVERT DECISIONT DECISIONT DECISIONT DECISIONT DECISION


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OTHER APPLICATIONSRETRACTION & ISOLATION

VALVE

... AND SENSOR SAFEL... AND SENSOR SAFEL... AND SENSOR SAFEL... AND SENSOR SAFEL... AND SENSOR SAFELY REMOY REMOY REMOY REMOY REMOVEDVEDVEDVEDVED

SENSOR IN OPERASENSOR IN OPERASENSOR IN OPERASENSOR IN OPERASENSOR IN OPERATIONTIONTIONTIONTION...............

The design of the K-Patents retractor & isolationvalve provides maximum safety for theoperation. The design eliminates the safety risk

resulting from partial closure of the isolationvalve and therefore activation of false divertalarms.

K-Patents Process Refractometers are used in variousconcentration measurements in the pulp and paperprocesses.

WEAK LIQUOR FROM PULPWEAK LIQUOR FROM PULPWEAK LIQUOR FROM PULPWEAK LIQUOR FROM PULPWEAK LIQUOR FROM PULP

WWWWWASHERSASHERSASHERSASHERSASHERSBlack liquor concentration is measured with K-PatentsProcess Refractometer to optimize the consumption ofpulp chemicals and usage of water in the washing.The material balances can be calculated and theefficiency of the washing process can be maximized.

BLACK LIQUOR TBLACK LIQUOR TBLACK LIQUOR TBLACK LIQUOR TBLACK LIQUOR TO EVO EVO EVO EVO EVAPORAAPORAAPORAAPORAAPORATTTTTORSORSORSORSORSThe concentration of feed liquor from washers toevaporation can be kept constant by controlling themixing liquor with the K-Patents refractometer, thusallowing the capacity of the evaporators to bemaximized. Using K-Patents in the intermediate stage

the profitablity can be increased in the form ofminimized steam consumption.

RECORECORECORECORECOVERY BOILER HEAVERY BOILER HEAVERY BOILER HEAVERY BOILER HEAVERY BOILER HEAT ENERGT ENERGT ENERGT ENERGT ENERGYYYYYK-Patents Process Refractometer can be used as a partof an advanced control system to measure the blackliquor refractive index fed to the liquor sprayers. Therefractive index is the best measure of the black liquorenergy content. This way the heat energy value of therecovery boiler can be determined.

GREEN LIQUOR TTGREEN LIQUOR TTGREEN LIQUOR TTGREEN LIQUOR TTGREEN LIQUOR TTA INA INA INA INA IN

CAUSTICIZINGCAUSTICIZINGCAUSTICIZINGCAUSTICIZINGCAUSTICIZINGBetter control of the green liquor in the causticizingprocess leads to increased capacity of the kraft cookingprocess. Green liquor total titratable alkali (TTA) contentcan be controlled by addition of weak wash liquordilution. TTA has a good correlation with RefractiveIndex, which provides an accurate measurement forthe green liquor. The K-Patents refractometer designtogether with the high pressure prism wash is ideal forthe heavy scaling conditions of the green liquor process.

STSTSTSTSTARCHARCHARCHARCHARCH, SIZING CHEMICALS AND, SIZING CHEMICALS AND, SIZING CHEMICALS AND, SIZING CHEMICALS AND, SIZING CHEMICALS AND

ADDITIVESADDITIVESADDITIVESADDITIVESADDITIVES

The final concentration and the quality of the cookedstarch can be verified by using the K-Patents in thecooking control. In the size press the concentration ofthe sizing chemicals or starch added to the paper canbe optimized for different paper grades and this waythe best quality for each grade can be achieved.


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ALL-DIGITAL DESIGN

The K-Patents Digital Divert Control System iscompletely microprocessor controlled. Allanalog circuitry has been eliminated. Thedigital signal transmission and microprocessorimplemented diagnostics ensure error freeoperation.

The system eliminates false alarms, becauseit reacts only when the level of solids truly fallsbelow the safe limit.

K-Patents DD-01

eliminates false

divert alarms


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SPECIFICATIONS

We reserve right to technical alterations.

The K-Patents DD-01 Digital Divert Control System isbuilt strictly according to the principles ofRecommended Good Practice for Safe Firing of Black

Liquor in Black Liquor Recovery Boilers (BLRBAC, August1982, revised March 2001).

KKKKK-P-P-P-P-PAAAAATENTSTENTSTENTSTENTSTENTS, INC., INC., INC., INC., INC.

1804 CENTRE POINT CIRCLESUITE 106, NAPERVILLEIL 60563, U.S.A.PHONE: (630) 955 1545FAX: (630) 955 [email protected]

KKKKK-P-P-P-P-PAAAAATENTS OTENTS OTENTS OTENTS OTENTS OYYYYY

P.O. BOX 77ELANNONTIE 5FIN-01511 VANTAA, FINLANDPHONE: INT.+358-9-8256 640FAX: INT.+358-9-8256 6461E-MAIL: [email protected]: WWW.KPATENTS.COM

Two K-Patents Process Refractometers PR-01-S (Aand B) are installed in series in the main black liquorline. Each refractometer is complete with a sensor,an indicating transmitter and interconnecting cables.Each refractometer provides also a measurementsignal not used by the divert control system.

The Divert Cont ro l Unit is contained in one

enclosure. The unit includes an operator panel andcontrol logics. The unit provides contact outputs forprism wash and black liquor diversion.

Two Retraction & Isolation Valves HIMP-2-CR to allowsafe removal of the refractometers from a pipe withfull flow and pressure. The isolation valve includesa prism wash nozzle and two check valves; one forprism wash, one for stuffing box flush.

A roofed mount ing plate for mounting the twoindicating transmitters and the divert control unittogether.

THE DDTHE DDTHE DDTHE DDTHE DD-01 SYSTEM CONSISTS OF-01 SYSTEM CONSISTS OF-01 SYSTEM CONSISTS OF-01 SYSTEM CONSISTS OF-01 SYSTEM CONSISTS OF:::::

Desired scale, properties of process solution

Process temperature and pressure range

Process flow range and pipe diameter

Desired process connection

Length of interconnecting cables

Supply voltage and frequency

Options and accessories

ORDERING INFORMAORDERING INFORMAORDERING INFORMAORDERING INFORMAORDERING INFORMATIONTIONTIONTIONTION:::::

dd-01_brochure[1].pdf

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